The present invention relates to an imaging unit, a camera body and a camera system.
Digital cameras for recording still images in a form of digital data have become extremely popular. Most of the commercially available digital cameras include a lens unit, an imagining device and an image processor integrally fixed to a camera body.
Because of such a structure of the digital camera, if a user wishes to enjoy a technical progress newly achieved in any of the camera body, lens unit, imaging device or the image processor, for example an increase in lens zoom magnification, improvement in mechanical shutter speed or in user-friendliness, achievement of a higher resolution, innovation in image processing technique or lower power consumption, the user is compelled to purchase an entire product embodying the improvement. This imposes a heavy economic burden to the user.
Accordingly, it is economically beneficial to the user to provide a digital camera that has an imaging unit including the imaging device and the image processor, removably mounted to the camera body, since the user can enjoy a technical progress simply by repurchasing the imaging unit only, when the progress is associated with the imaging unit, or the camera body only when the progress is related to the camera body.
Japanese Patent Provisional Publication No. HEI 10-271376 (hereafter, referred to as a document 1) discloses a digital camera including an imaging unit (specifically a camera main unit in the cited document 1) and a camera body (specifically a lens unit in the cited document) removably combined, though a design concept of this digital camera may be different from the foregoing viewpoint to some extent. The imaging unit disclosed therein includes a lid that protects the imaging device from dust or foreign substance when detached from the camera body, and a lid opening/closing mechanism. When the imaging unit is attached to the camera body, a power source included in the camera body supplies a current that drives the lid opening/closing mechanism to open the lid (Ref. paragraph 0020 and FIGS. 2 and 5 of the cited document 1).
However, the lid opening/closing mechanism has a complicated structure including an electromagnet and a link mechanism, which makes the camera larger in dimensions and increases the manufacturing cost. Besides, such a complicated structure is prone to incur a malfunction or failure.